Aim: How do we determine the first n terms of a geometric series? (This formula is listed on the Regents Reference Sheet as Sum of a Geometric Series)

At the end of the lesson, you will be able to...
  1. define geometric series
  2. compare and contrast a geometric sequence with a geometric series
  3. explore and discover the formula for finding the sum of n terms of a geometric series
  4. apply the formula to problems when given as a sum or described verbally

As you watch the videos, answer the following questions...
1. What is a geometric series?
2. How does a geometric series differ from a geometric sequence?
3. Write the formula in your notebook.

Notice how in the videos, the instructors write the information they need to know on the side to organize themselves before they begin the work

Video 1


This next video shows you two problems. You may ignore the second problem as we have not learned that yet.

Video 2

Homework: Work on problems 3-13 odd, 23, 25, 27

Geo_Series.JPG

Answers:

A-Geo_Series.JPG

Journal entry: Describe a real-world situation that involves finding the sum of a geometric series. Indicate what the common ratio is in your description.